In accordance with the present state of the printing art, a printing press has one or more ink reservoirs and there is a plurality of adjusting screws disposed along the outlet section of each reservoir. The screws may be adjusted to permit more or less ink flow from the position of the reservoir that the screw controls. It is important that the ink flow be as correct as possible. A color as it appears to the human eye is dependent upon the depth of the ink supplied or transferred to the paper or webbing that the person is viewing. If the ink flow is too little then the amount of ink applied to the image areas of the printing plate (which represent the image to be printed) will be insufficient. Therefore when said ink is transferred to the paper, the ink density will be inadequate and the image on the paper will not appear to be of the color desired by the user. Likewise if the ink flow is too great, the amount of transferred ink will be excessive and the ink density too great to provide the proper color to the viewer.
Currently an operator of a printing press, employing prior art techniques and equipment, examines the printing plate and makes a value judgment, based on experience, as to what the settings of the ink flow keys or adjustment screws should be. By eye he attempts to estimate the amount of printing area on the printing plate which lies along a zone, or in line, opposite an associated ink adjustment screw. Since printing areas may consist of solids, halftones, type and discontinuous patterns, such an empirical value judgement is usually extremely inaccurate even with highly experienced operators. Nonetheless in the present state of the art he then sets the screws at the values his experience dictates and he makes a "run" of material, i.e. paper or webbing, upon which he prints images in order to check the colors. Printing presses very often run at speeds of 1500 feet per minute or higher. As can be readily understood, in the current state of the art, very often a number of "makeready" runs are necessary so that repeated adjustments of the keys or adjustment screws can be made in order to obtain the desired colors of the images. Such repeated "makeready" runs represent a great waste of paper and of course a great waste of time. Heretofore there has been little basis, other than empirical, for setting the keys or adjustment screws of the printing press, and even the empirical basis relied on a series of trial and error runs during the "makeready" period. It should also be understood that in an empirical technique for setting the ink feed screws on a press, any adjustment requires a large number of impressions before a new equilibrium point is reached and the adjustment can be evaluated. The foregoing is caused by the reservoir of ink in the roller train being fed by the ink fountain systems.
The present invention enables the printing press operator to electronically scan the printing plate in order to determine the ratio of printing area to nonprinting area along every zone of the printing plate which is controlled by an adjustment screw. The adjustment screws can then be set to control the rate of ink flow along those zones or tracks of the printing plate.